Adhesive tapes and adhesive materials, such as epoxy, acrylics, cyanate ester, have been used for temporary bonding in wafer processing. During wafer processing, a wafer may be temporarily bonded to a support substrate and later released from bonding to the support substrate after certain processing operations. For example, a wafer may be temporarily bonded to a glass substrate for support during the grinding of the backside of the wafer before backside metal (BSM) deposition. Backside grind may be performed to thin the wafer and aid sawing the wafer into chips for packaging and/or to rough the backside surface for improved adhesion of backside metal, such as Gold. After the backside grind and backside metal deposition, the support substrate is detached from the wafer.
There exist commercially available adhesive tapes with the capability of ultraviolet (UV) light activated release of temporary bonding. The adhesion of the UV-releasing tapes reduces greatly after the exposure to the UV light. Such tapes may be used as wafer dicing tapes, providing temporary bonding of the wafer to the wafer dicing frame under the temperature of 80° C. or less in the absence of the UV light.